diff options
| author | Parav Pandit <parav@nvidia.com> | 2021-06-10 10:01:11 +0800 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2021-06-10 09:06:13 +0200 |
| commit | 1f106ff0ea2782a6bc49bb927e4789681a2ec507 (patch) | |
| tree | 4ddb0c1d7b8cc24224ddda6f19a0362ea657c6cf /include/linux/intel-iommu.h | |
| parent | 3bc770b0e998a69c7085ec36405eda246b5b10d8 (diff) | |
iommu/vt-d: Use bitfields for DMAR capabilities
IOTLB device presence, iommu coherency and snooping are boolean
capabilities. Use them as bits and keep them adjacent.
Structure layout before the reorg.
$ pahole -C dmar_domain drivers/iommu/intel/dmar.o
struct dmar_domain {
int nid; /* 0 4 */
unsigned int iommu_refcnt[128]; /* 4 512 */
/* --- cacheline 8 boundary (512 bytes) was 4 bytes ago --- */
u16 iommu_did[128]; /* 516 256 */
/* --- cacheline 12 boundary (768 bytes) was 4 bytes ago --- */
bool has_iotlb_device; /* 772 1 */
/* XXX 3 bytes hole, try to pack */
struct list_head devices; /* 776 16 */
struct list_head subdevices; /* 792 16 */
struct iova_domain iovad __attribute__((__aligned__(8)));
/* 808 2320 */
/* --- cacheline 48 boundary (3072 bytes) was 56 bytes ago --- */
struct dma_pte * pgd; /* 3128 8 */
/* --- cacheline 49 boundary (3136 bytes) --- */
int gaw; /* 3136 4 */
int agaw; /* 3140 4 */
int flags; /* 3144 4 */
int iommu_coherency; /* 3148 4 */
int iommu_snooping; /* 3152 4 */
int iommu_count; /* 3156 4 */
int iommu_superpage; /* 3160 4 */
/* XXX 4 bytes hole, try to pack */
u64 max_addr; /* 3168 8 */
u32 default_pasid; /* 3176 4 */
/* XXX 4 bytes hole, try to pack */
struct iommu_domain domain; /* 3184 72 */
/* size: 3256, cachelines: 51, members: 18 */
/* sum members: 3245, holes: 3, sum holes: 11 */
/* forced alignments: 1 */
/* last cacheline: 56 bytes */
} __attribute__((__aligned__(8)));
After arranging it for natural padding and to make flags as u8 bits, it
saves 8 bytes for the struct.
struct dmar_domain {
int nid; /* 0 4 */
unsigned int iommu_refcnt[128]; /* 4 512 */
/* --- cacheline 8 boundary (512 bytes) was 4 bytes ago --- */
u16 iommu_did[128]; /* 516 256 */
/* --- cacheline 12 boundary (768 bytes) was 4 bytes ago --- */
u8 has_iotlb_device:1; /* 772: 0 1 */
u8 iommu_coherency:1; /* 772: 1 1 */
u8 iommu_snooping:1; /* 772: 2 1 */
/* XXX 5 bits hole, try to pack */
/* XXX 3 bytes hole, try to pack */
struct list_head devices; /* 776 16 */
struct list_head subdevices; /* 792 16 */
struct iova_domain iovad __attribute__((__aligned__(8)));
/* 808 2320 */
/* --- cacheline 48 boundary (3072 bytes) was 56 bytes ago --- */
struct dma_pte * pgd; /* 3128 8 */
/* --- cacheline 49 boundary (3136 bytes) --- */
int gaw; /* 3136 4 */
int agaw; /* 3140 4 */
int flags; /* 3144 4 */
int iommu_count; /* 3148 4 */
int iommu_superpage; /* 3152 4 */
/* XXX 4 bytes hole, try to pack */
u64 max_addr; /* 3160 8 */
u32 default_pasid; /* 3168 4 */
/* XXX 4 bytes hole, try to pack */
struct iommu_domain domain; /* 3176 72 */
/* size: 3248, cachelines: 51, members: 18 */
/* sum members: 3236, holes: 3, sum holes: 11 */
/* sum bitfield members: 3 bits, bit holes: 1, sum bit holes: 5 bits */
/* forced alignments: 1 */
/* last cacheline: 48 bytes */
} __attribute__((__aligned__(8)));
Signed-off-by: Parav Pandit <parav@nvidia.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210530075053.264218-1-parav@nvidia.com
Link: https://lore.kernel.org/r/20210610020115.1637656-20-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'include/linux/intel-iommu.h')
| -rw-r--r-- | include/linux/intel-iommu.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h index f5cf31dd7280..2621eff04c82 100644 --- a/include/linux/intel-iommu.h +++ b/include/linux/intel-iommu.h @@ -546,7 +546,10 @@ struct dmar_domain { * domain ids are 16 bit wide according * to VT-d spec, section 9.3 */ - bool has_iotlb_device; + u8 has_iotlb_device: 1; + u8 iommu_coherency: 1; /* indicate coherency of iommu access */ + u8 iommu_snooping: 1; /* indicate snooping control feature */ + struct list_head devices; /* all devices' list */ struct list_head subdevices; /* all subdevices' list */ struct iova_domain iovad; /* iova's that belong to this domain */ @@ -558,9 +561,6 @@ struct dmar_domain { int agaw; int flags; /* flags to find out type of domain */ - - int iommu_coherency;/* indicate coherency of iommu access */ - int iommu_snooping; /* indicate snooping control feature*/ int iommu_count; /* reference count of iommu */ int iommu_superpage;/* Level of superpages supported: 0 == 4KiB (no superpages), 1 == 2MiB, |